Homeless advocates say recent incidents make it seem like police have an extra focus on The City’s most vulnerable people.

The City's homeless advocates and police often don't get along, but an incident last week may show how relations between supporters of San Francisco's street people and its constables are worse than usual.

In what some homeless advocates say is the latest in a series of jabs aimed their way, about six people were camped out underneath the freeway overpass at Eighth and Brannan streets Thursday, next to a banner attached to a fence that read "Stop the Criminalization of the Homeless."

As the Coalition on Homelessness' biggest fundraiser of the year went on at a nearby art space, a pair of police officers arrived and tried to get the street sleepers to move along, said Paul Boden, a former coalition executive director who witnessed the incident.

The police were eventually persuaded to leave without issuing tickets or calling the Department of Public Works to remove the tents and the campers' belongings, but the message was clear, coalition members said Friday.

"Our whole agenda for the last year has been trying to stop the criminalization of homelessness in San Francisco," said Matthew Gerring, editor of the Street Sheet newspaper that many city street people sell for a dollar. "For this to happen on the night of our fundraiser is just another example. ... We're very disappointed that they would do that."

A police spokesman said late Friday that no information on the specific incident was available, but that police responded to "citizen complaints" of illegal camping.

When police receive a complaint from the public, "if officers respond and see that there are tents and/or structures erected, they have the authority to ask them to break down those structures since it's a violation of city ordinance," Officer Gordon Shyy said.

The area in question is mostly commercial, with Airbnb's headquarters nearby.

Homelessness in The City appears to be as serious a problem as ever despite record municipal spending and record-low unemployment.

There are more than 6,400 people on the streets in The City on any given night, a figure that's held relatively stable since 2005.

The officers last week used The City's sit-lie ordinance to get the campers to move along, Boden said. That law, approved by voters in 2010, makes sitting or lying on public right-of-ways a citable offense.

In recent years, laws closing The City's parks at night -- allowing police to issue a trespassing citation on top of tickets for violating bans on sleeping in parks -- and banning large recreational vehicles in areas where people frequently sleep in them have also passed.

And this year, BART police have begun clearing out the Powell and Civic Center stations after years of "turning a blind eye" to the homeless folks congregating in hallways, Boden said.

This chain of actions has led advocates to believe there was no mistake that the homeless camp in question would receive a police visit.

"There are any number of tent camps anywhere in San Francisco at any given moment," Boden said. "The fact they would choose to go after that one feels deliberate."